Primary patency is defined as hemodynamic evidence of blood flow through an open graft that has maintained uninterrupted patency and has not previously undergone a revision to restore blood flow. A disadvantaged autologous vein is defined as meeting at least one of the two following criteria: (1) Any autologous vein(s) other than greater saphenous vein deemed usable by the Investigator; (2) Usable ipsilateral or contralateral autologous greater saphenous vein that meets any of the following criteria: (a) Diameter of less than or equal to 3.0 mm; (b) Inadequate length requiring splicing; (c) Poor quality vein that is either sclerotic or phlebitic.